This proposal outlines plans to establish a new program for training physician scientists in clinical investigation at the Yale School of Medicine. The centerpiece of the program is a new initiative, the Experimental Medicine Program, which will award advanced degrees through the Department of Medicine to clinical fellows from a multitude of clinical departments. This program was designed to recognize the advanced training status and the special career orientation of clinical fellows, by providing a protected and supportive environment conducive to prolonged training in clinical investigation. The two training pathways within the program- the Clinical Strategies Pathway and the Disease-Oriented Pathway - will both consist of a rigorous curriculum of coursework, of mentored research under the tutelage of a clinical faculty member, and of careful supervision by qualifying and thesis committees leading to the Ph.D. or D.Sc. degree after a period of four years. Additional trainees who will benefit from the curriculum and coursework include other fellows supported by T32 Institutional Training Grants at the Yale School of Medicine, recipients of K-08, K23, or CAP awards, and selected students from the Yale School of Nursing's Doctoral of Nursing Science Program. The current application is responsive to RFA OD-98-007 by designing a rigorous curriculum which provides cutting edge training in clinical investigation through new and existing coursework. The curriculum takes maximum advantage of the strong training environment already in place in the Medical School.